Zero-turn radius lawnmower with suspension system

ABSTRACT

Some embodiments of the invention provide a transaxle drive system for ride-on equipment. The transaxle drive system can include a frame supporting at least one power source and at least two subframes, the at least one power source including at least one drive pulley. The system can also include transaxle assemblies driven by at least a portion of at least one belt from the at least one drive pulley. The transaxle assemblies can include a first transaxle assembly supported by a subframe, the first transaxle assembly coupled to the at least one drive pulley with at least one belt, and a second transaxle assembly supported by another subframe, the second transaxle assembly coupled by at least one belt to the at least one drive pulley. The transaxle assemblies can be independently pivoted with respect to each other, the frame, and the power source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/652,905, filed on Jul. 18, 2017, which is acontinuation application of U.S. patent application Ser. No. 15/226,811,filed on Aug. 2, 2016, which is a continuation-in-part of U.S. patentapplication Ser. No. 15/082,765, filed Mar. 28, 2016, which is acontinuation application of U.S. patent application Ser. No. 13/840,070,filed Mar. 15, 2013, now U.S. Pat. No. 9,161,490, which claims priorityunder 35 U.S.C. 119 to U.S. Provisional Patent Application No.61/677,288, filed on Jul. 30, 2012, and U.S. Provisional PatentApplication No. 61/643,809, filed on May 7, 2012, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND

Hydrostatic transaxles have become prevalent in the ZTR mower industry.Hydrostatic transaxles combine the hydraulic pump and one or morehydraulic wheel motors into a single unit, thereby simplifying andreducing the overall cost of the drive system of ZTR mowers and otherhydraulically-driven devices. The hydraulic pump of the hydraulictransaxle is mechanically driven by an internal combustion engine (orsimilar drive unit) via a belt-and-pulley system, and the hydraulic pumpin turn drives the hydraulic motor for each drive wheel. However, due tothe integration of the hydraulic pump and hydraulic wheel motors into asingle unit, suspension of the drive wheels on a ZTR mower utilizinghydrostatic transaxles presents several challenges. One of the foremostchallenges is the variation in belt angle between the drive pulleycoupled to the power take-off shaft of the internal combustion engine,and the driven pulley(s) of the hydraulic pump on the hydrostatictransaxle. If the belt angle between the drive and driven pulley(s) istoo great, the belt may run off of one or more of the pulleys and renderthe drive system inoperable, or may wear at an unacceptable rate. Due tothese challenges, suspension of drive wheels driven by hydrostatictransaxles has been generally avoided.

SUMMARY

Some embodiments of the invention a transaxle drive system for ride-onequipment comprising a frame supporting at least one power sourceincluding at least one drive pulley and at least two subframes. Someembodiments include a plurality of transaxle assemblies configured andarranged to be driven by at least a portion of at least one belt fromthe at least one drive pulley. In some embodiments, the plurality oftransaxle assemblies comprise a first transaxle assembly supported by asubframe that is coupled to the at least one drive pulley with at leasta portion of at least one belt. Further, some embodiments include asecond transaxle assembly supported by another subframe and coupled byat least a portion of at least one belt to the at least one drivepulley. In some embodiments, the plurality of transaxle assemblies areconfigured and arranged to be independently pivoted with respect to eachother, the frame, and the power source.

In some embodiments, the at least one power source includes at least oneauxiliary drive pulley coupled to a power take-off shaft. In someembodiments, the at least one auxiliary drive pulley is positionedbetween the plurality of transaxle assemblies and rear wheels of amower. In some embodiments, the mower includes a mower deck positionedbetween front and rear wheels of the mower, and the mower deck coupledto and supported by the frame. In some further embodiments, the mowerdeck comprises a cutter assembly coupled to and configured to be drivenby the auxiliary drive pulley using at least one endless belt.

In some embodiments, at least one of the subframes is coupled to theframe using at least one compressible component. In some embodiments,the at least one compressible component comprises rubber or otherelastomeric polymer. In some embodiments, the plurality of transaxleassemblies include drive axles configured and arranged to enable drivewheels to be independently suspended by the at least two subframes. Insome embodiments, the at least two subframes are positioned coupled toopposite sides of the frame.

Some embodiments include a plurality of transaxle assemblies that arepositioned between the cutter assembly and the at least one auxiliarydrive pulley. In some embodiments, the subframes each include a pivotcoupled to the frame about a pivot axis. In some embodiments, the pivotaxis of each subframe are parallel. In some embodiments, at least one ofthe first transaxle assembly and second transaxle assembly comprises ahydrostatic transaxle. In some embodiments, at least one of the firsttransaxle assembly and second transaxle assembly are configured andarranged to be belt-driven by the at least one power source duringpivotal motion about the frame.

Some further embodiments comprise a pulley and belt drive assemblyincluding at least one belt idler pulley positioned outside of thesubframes and supported by the frame, and at least one endless beltcoupled with the at least one belt idler pulley and at least one drivenpulley, where the at least one driven pulley positioned suspended by atleast one of the subframes. In some embodiments, the pulley and beltdrive assembly further comprises at least one backside idler pulleycoupled to the least one endless belt. In other embodiments, the atleast one endless belt is further coupled with the at least one drivepulley, where the at least one backside idler pulley is configured andarranged to pivot with respect to the at least one drive pulley.

In some further embodiments of the invention, the at least one drivepulley is driven by a drive shaft of the at least one power source,where the drive shaft includes an axis of rotation. In some embodiments,the first transaxle assembly is configured and arranged to be driven bythe at least one power source while pivoting about the axis of rotation.In other embodiments, the second transaxle assembly is configured andarranged to be driven by the at least one power source while pivotingabout the axis of rotation and the first transaxle assembly.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an isometric view of a ZTR mower in accordance withsome embodiments of the invention.

FIG. 2 illustrates a side sectional view of ZTR mower components inaccordance with some embodiments of the invention.

FIG. 3 illustrates a side sectional view of ZTR mower components inaccordance with some embodiments of the invention.

FIG. 4A shows a perspective view of ZTR mower components and suspensionsystem in accordance with some embodiments of the invention.

FIG. 4B shows a partial perspective view of ZTR mower components andsuspension system in accordance with some embodiments of the invention.

FIG. 5 shows a side sectional view of a suspension system in accordancewith another embodiment of the invention.

FIG. 6 shows a side sectional view of a suspension system in accordancewith another embodiment of the invention.

FIG. 7 illustrates a perspective view of a hydrostatic transaxle controlsystem in accordance with embodiments of the invention.

FIG. 8 shows a side sectional view of a hydrostatic transaxle controlsystem in accordance with one embodiment of the invention.

FIG. 9 shows a side sectional view of a hydrostatic transaxle controlsystem in accordance with another embodiment of the invention.

FIG. 10A illustrates a perspective close-up view of the lower portion ofthe compensated control linkage assembly in accordance with anotherembodiment of the invention.

FIG. 10B illustrates a perspective close-up view of the upper portion ofthe compensated control linkage assembly in accordance with anotherembodiment of the invention.

FIG. 11 illustrates a perspective view of a subframe and hydrostatictransaxles in accordance with some embodiments of the invention.

FIG. 12 illustrates a perspective view of a subframe and hydrostatictransaxles in accordance with some embodiments of the invention.

FIG. 13 illustrates a top sectional view of the hydrostatic transaxledrive system components in accordance with some embodiments of theinvention.

FIG. 14A illustrates a close-up perspective view of a hydrostatictransaxle drive system in accordance with some embodiments of theinvention.

FIG. 14B illustrates a close-up perspective view of a hydrostatictransaxle drive system in accordance with some embodiments of theinvention.

FIG. 15 illustrates a partially transparent perspective view of aportion of a suspension system of a ZTR mower in accordance with someembodiments of the invention.

FIG. 16 illustrates a perspective view of components of a suspensionsystem of a ZTR mower in accordance with some embodiments of theinvention.

FIG. 17 illustrates a top view of components of a suspension system of aZTR mower in accordance with some embodiments of the invention.

FIG. 18 illustrates an end view of a suspension system of a ZTR mower inaccordance with some embodiments of the invention.

FIG. 19 illustrates a side view of a suspension system of a ZTR mower inaccordance with some embodiments of the invention.

FIG. 20 illustrates a partially transparent side view of a suspensionsystem of a ZTR mower in accordance with some embodiments of theinvention.

FIG. 21 illustrates a perspective view of a suspension system of a ZTRmower in accordance with some embodiments of the invention.

FIG. 22 illustrates a close up perspective view of a portion of asuspension system of a ZTR mower in accordance with some embodiments ofthe invention.

FIG. 23 illustrates a close up detailed sectional view of a suspensionsystem of a ZTR mower in accordance with some embodiments of theinvention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

The following discussion is presented to enable a person skilled in theart to make and use embodiments of the invention. Various modificationsto the illustrated embodiments will be readily apparent to those skilledin the art, and the generic principles herein can be applied to otherembodiments and applications without departing from embodiments of theinvention. Thus, embodiments of the invention are not intended to belimited to embodiments shown, but are to be accorded the widest scopeconsistent with the principles and features disclosed herein. Thefollowing detailed description is to be read with reference to thefigures, in which like elements in different figures have like referencenumerals. The figures, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope ofembodiments of the invention. Skilled artisans will recognize theexamples provided herein have many useful alternatives and fall withinthe scope of embodiments of the invention.

FIG. 1 illustrates an isometric view of a ZTR mower 10 in accordancewith some embodiments of the invention. The ZTR mower 10 can include amain frame 102, front caster wheels 106, and rear drive wheels 104 and aseat 12. The ZTR mower 10 can also include a mower deck 31 including afront cutter assembly 30 positioned between the front caster wheels 106and rear wheels 104. Some embodiments can include front caster wheels 35mounted to the front cutter assembly 30 that aid in maintaining theheight of the front cutter assembly 30, thereby preventing damage fromrocks and other large debris. In some embodiments, the ZTR mower 10includes at least one power source. For example, in some embodiments,the mower 10 can include an engine, such as an internal combustionengine 108 shown behind the seat 12 in FIG. 1. In some embodiments, theengine 108 can be coupled to a power take-off shaft 109 (not shown). Insome embodiments, the power take-off shaft 109 is coupled to at leastone hydrostatic axles 114 (not shown) via an endless belt 132 (notshown). In some further embodiments, the ZTR mower 10 can also includeleft and right control paddles assemblies 134. In some furtherembodiments, the ZTR mower 10 can include alternative paddle assembly134 arrangements.

FIG. 2 shows a side sectional view of various ZTR mower components inaccordance with one embodiment of the invention. For ease ofunderstanding, many conventional components commonly present in ZTRmowers (e.g., control handles, seat, mower deck, etc.) have been omittedfrom FIG. 2. However, one of ordinary skill in the art will readilyunderstand that such conventional components may be included in theembodiments described herein. In some embodiments, the ZTR mower 10 ofFIG. 2 comprises a main frame 102 supporting both rear drive wheels 104and front caster wheels 106. In some embodiments, the main frame 102further supports an internal combustion engine 108, which operates todrive both the drive wheels 104, other primary components, as well asone or more auxiliary components attached to the ZTR mower 10, such asthe cutting blades of the front cutter assembly 30 (shown in FIG. 1).Some embodiments include the internal combustion engine 108 capable ofdriving the drive wheels 104 in addition to other components via one ormore drive pulleys, including a drive pulley 110 mounted to a powertake-off shaft 109 extending therefrom.

In some embodiments, the ZTR mower 10 as illustrated in FIG. 2 furtherincludes a subframe 112 including a first axis 112 a pivotally mountedto main frame 102 about a pivot 115 including a pivot axis 116. In someembodiments, the subframe 112 may be mounted to main frame 102 using analternative technology that allows for substantially translationalmovement. In some embodiments, the subframe 112 supports thereon one ormore transaxle assemblies 114 a. For example, some embodiments includeone or more hydrostatic transaxles 114. In some embodiments, thetransaxles 114 contain both a hydraulic pump, a hydraulic valve (notshown), and a hydraulic motor (not shown) for powering the drive wheels104. Some embodiments can include one or more belt idler pulleys 118mounted on the subframe 112. In some further embodiments, the subframe112 further supports one or more backside idler pulleys 120 a, 120 b. Inother embodiments, idler pulley(s) 118 and backside idler pulleys 120 aand 120 b are attached to the subframe 112 via a spindle (not shown) toallow rotation of the pulley, and in some other embodiments, they can beattached via a plate 124, which may be integrally formed from thesubframe 112. In some embodiments, idler pulley(s) 118 and backsideidler pulleys 120 a, 120 b receive an endless belt 132 (not shown) thatis driven by drive pulley 110 on the power take-off shaft 109 ofinternal combustion engine 108. In some embodiments, the endless belt132 is also received by pulleys 122 a, 122 b coupled to the hydraulicpump of hydrostatic transaxle 114. In some embodiments of the invention,through this pulley-belt coupling, power from the internal combustionengine 108 is transferred to hydrostatic transaxle 114 via powertake-off shaft 109 to operate drive wheels 104. In some otherembodiments, alternative methods of driving hydrostatic transaxle 114,such as through a universal drive shaft can be used.

FIG. 3 shows another side sectional view of various ZTR mower componentsin accordance with one embodiment of the invention. As illustrated inthis view, the subframe 112 has travelled counterclockwise about pivotaxis 116 to illustrate a compressed state of the suspension system 103.As can be seen, each of the components mounted on subframe 112 rotateabout pivot axis 116, including idler pulley(s) 118, backside idlerpulleys 120, and at least one driven pulley 122 a, 122 b on hydrostatictransaxle 114. In some embodiments, power is transmitted from the drivepulley 110 via an endless belt 132. In some embodiments, the endlessbelt 132 can be an “A” section belt, although in other embodiments, a“V” section belt, a flat belt, or other type of belt can be used.

In some embodiments, as the suspension travels, the belt angle onlychanges between the back side idler pulleys 120 a, 120 b and the drivepulley 110 where the distance between these particular pulleys is thegreatest. Most notably, idler pulley(s) 118 and backside idler pulleys120 a,120 b travel in the same plane (shown as pulley plane 400 in FIGS.14A and 14B) as the driven pulley 122 a, 122 b upon rotation about pivotaxis 116, which prevents belt misalignment between these pulleys whensubframe 112 travels through its suspension arc. As described earlier,if the idler pulleys 118, 120 a, 120 b were to travel or rotate about adifferent plane than driven pulleys 122 a, 122 b on hydrostatictransaxle 114 (i.e. not within pulley plane 400), significant beltmisalignment may cause the belt 132 to “jump” or run off of the pulleysystem and render the system inoperable. However, as shown in comparingFIG. 2 and FIG. 3, the only belt angle change between pulleys in thepresent embodiment would be between backside idler pulleys 120 a,120 band drive pulley 110 mounted to the power take-off shaft 109. The riskof belt “jump” due to misalignment is greatly diminished under thisconstruction because there is a significant distance between backsideidler pulleys 120 a,120 b and drive pulley 110, thereby minimizing thebelt angle change when subframe 112 travels through its suspension arc.Furthermore, in general, backside idler pulleys 120 a,120 b have ahigher tolerance for belt angle changes during operation than othertypes of pulleys, and therefore the risk of the belt 132 decoupling isgreatly diminished.

FIGS. 4A and 4B show perspective views of various ZTR mower componentsin accordance with one embodiment of the invention. As discussedpreviously, the subframe 112 is pivotally coupled to main frame 102 at apivot 115 including a pivot axis 116. In some embodiments, the subframe112 comprises a first support 214 including a first end 214 a and asecond end 214 b, and a second support 216 having a first end 216 a anda second end 216 b. In some embodiments, the first support 214 andsecond support 216 are coupled by at least one substantiallyperpendicular and substantially horizontal third support 218. In someembodiments, the third support 218 is coupled to the second end 214 b ata third support first end 218 a, and the third support 218 is coupled tothe second end 216 b at a third support second end 218 b. As discussedearlier, in some embodiments, the subframe 112 including a first axis112 a is pivotally mounted to the main frame 102 about a pivot 115including a pivot axis 116. In some embodiments, a pivot 115 is coupledto the first end 214 a of the first support 214 and the first end 216 aof the second support 216.

In some further embodiments, the subframe 112 is further coupled to amotion absorbing suspension component. In some embodiments, the motionabsorbing suspension component can include a compressible suspensioncomponent such as a coil spring-type suspension component 126. In someembodiments, a first end 126 a of the compressible suspension component126 is coupled to the main frame 102, and a second end 126 b of thecompressible suspension component is coupled to the subframe 112. Insome embodiments, the suspension component 126 is coupled to a secondend 214 b of the first support 214 or a second end 216 b of the secondsupport 216, or both.

In the perspective view of FIG. 4A, the subframe 112 is shown extendingcontinuously between both the right and left sides of main frame 102 tohold two hydrostatic transaxles 114, each of which can drive a separatedrive wheel 104 (not shown). As shown, the subframe 112 holds bothhydrostatic transaxles 114, each drive wheel 104 (not shown), and istranslated about the suspension arc of subframe 112 as the ZTR mower 10travels across varying terrain. In some embodiments, the subframe 112need not extend continuously between the right and left sides of themain frame 102.

FIG. 5 shows another side sectional view of the suspension system 103according to one embodiment of the invention. In some embodiments, oneof the drive wheels 104 has been omitted from the figure for clarity. Asshown, in some embodiments, a compressible suspension component, such asthe coil spring-type suspension component 126 is pivotally coupled toboth main frame 102 (shown as 126 a) and subframe 112 (shown as 126 b).This arrangement allows for restricted rotation of subframe 112 aboutpivot axis 116. In some other embodiments, the coil spring-typesuspension component 126 can be replaced by any appropriate shockabsorber. In some embodiments, the subframe 112 is pivotally coupled toa link 128, which is in turn pivotally coupled to a bell crank 130. Someembodiments include link 128 and bell crank 130 coupled to a mower deck(not shown) to allow corresponding movement of the mower deck inassociation with movement of subframe 112. FIG. 6 shows a similar sidesectional view as that depicted in FIG. 5, but with coil spring-typesuspension component 126 in a compressed position. Again, a comparisonbetween FIG. 5 and FIG. 6 clearly shows that all components mounted uponsubframe 112 rotate about pivot axis 116, including any desired idlerpulleys (not shown) and the hydrostatic transaxle 114.

As discussed earlier, in some embodiments, the mower 10 can include afront cutter assembly 30 (FIG. 1 illustrates an isometric view of ZTRmower 10 in accordance with some embodiments of the invention and showsa front cutter assembly 30 positioned between the front caster wheels106 and rear wheels 104). As shown in FIG. 5 and FIG. 6, someembodiments of the invention include an auxiliary pulley 111. In someembodiments, the auxiliary pulley 111 can be coupled to the engine 108via a power transfer assembly (e.g. a clutch assembly not shown) toenable the rotational torque of the power take-off shaft 109 to drivethe cutter assembly 30 by an endless belt (not shown). In someembodiments, a user can control the coupling of the engine 108 to thecutter assembly 30 through a conventional power transfer assembly, andin some further embodiments, the user can control the rotational speedof the auxiliary pulley 111 to control the cutter assembly 30. In someother embodiments, further auxiliary pulleys can be coupled to the powertake-off shaft 109. In other embodiments, one or more further auxiliarypulleys (not shown) can be coupled to one or more further conventionalauxiliary components (not shown).

In some embodiments, the mower 10 can include other features. Forexample, in some embodiments, a control linkage assembly 133 can be usedto control the power provided by an internal combustion engine 108. Forexample, FIG. 7 shows a perspective view of a control linkage assembly133 for operator control of hydrostatic transaxle 114. In someembodiments, one or more hydrostatic transaxles 114 that combine ahydraulic pump (not shown) and hydraulic wheel motor (not shown) into asingle unit, are coupled to the engine 108 by a pulley and belt driveassembly 117. In some embodiments, an operator can deploy one or morecontrol paddles 134 to manipulate at least one hydrostatic transaxle 114to drive the drive wheels 104 (not shown). In some embodiments, anoperator can deploy one or more control paddles 134 to manipulate atleast one hydrostatic transaxle 114 to move in either a forward orreverse direction, or to remain neutral. In some embodiments, one ormore control paddles 134 coupled to the ZTR mower 10 can be coupled to ahydrostatic transaxle pump valve (not shown) to allow the control ofhydraulic fluid from one or more hydraulic pumps (not shown) within thehydrostatic axles 114.

As shown previously in FIGS. 4-6, in some embodiments, when the mower 10traverses a terrain, or when mower 10 is loaded and unloaded, the mainframe 102 can move with respect to the subframe 112. For example, whenan operator mounts the mower 10, or if additional weight or equipment isloaded onto the mower 10, the frame 102 can move with respect to thesubframe 112. Furthermore, during loading of the mower 10, in someembodiments, the coil spring-type suspension component 126, pivotallycoupled to both main frame 102 with the pivot 115, can compress, and thesubframe 112 can pivot about the pivot axis 116 on pivot 115. In someembodiments, because the subframe 112 can change the orientation ofhydrostatic transaxle 114 during a compressed condition, any directlinkage to hydrostatic transaxle 114 may cause an undesirable actuationof the hydrostatic transaxle pump valve (not shown) if one or morecontrol paddle(s) 134 were to be directly coupled to hydrostatictransaxle 114. Such an undesirable actuation of the hydrostatictransaxle pump valve may be unperceivable when the ZTR mower 10 ismoving, however it can become significantly more noticeable when the ZTRmower 10 is in the parked or neutral condition. In the parked or neutralcondition, compression of subframe 112 may occur due to operatormovement, or some other shifting of weight on the rear of the mower 10.If a direct linkage from control paddle(s) 134 to hydrostatic transaxle114 was used during such parked or neutral conditions, this weighting ofthe rear of the mower 10 may cause the linkage to open the hydrostatictransaxle pump valve enough to cause the machine to “lurch” until anunsuspended condition is again reached.

In some embodiments of the invention, a compensated control linkagesystem 133 can be used that comprises a first control linkage 136,including a first end 136 a and a second end 136 b, wherein the firstend 136 a is coupled to control paddle assembly 134, and the second end136 b is coupled to a first end 138 a of a bell crank 138. In someembodiments, the bell crank 138 is pivotally coupled to a component thatis coupled to the subframe 112 via a pivot axis 138 c. For example, asshown in FIG. 10b , the bell crank 138 can be pivotally coupled to thecompensator arm 310 by pivot point 138 c. In some embodiments, a secondend 138 b of a bell crank 138 can be coupled to a first end 140 a of asecond control linkage 140. In some further embodiments, the second end140 b of a second control linkage 140 can be coupled to a second bellcrank (bell crank 142) used in operation of the hydrostatic transaxlepump valve (not shown). Most notably, in some embodiments, thecompensated control linkage system 133 straddles two regions of themower 10 that are supported around a pivoting component, pivot 115including pivot axis 116, the main frame 102 and the subframe 112. Someembodiments include a first control linkage 136 coupled via first end136 a to a paddle assembly 134 that is anchored to one region (the mainframe 102). Some embodiments also include the second end 136 b of firstcontrol linkage 136 coupled to a bell crank 138 that is directly coupledto compensator arm 310, which is anchored to the subframe 112.Therefore, in some embodiments, the bell crank 138 interposed betweenthe first control linkage 136 and second control linkage 140 asdescribed above can compensate for movement of subframe 112 and rotationabout pivot axis 116.

The embodiments as described can be further illustrated in FIG. 8 andFIG. 9 showing detailed side sectional views of the compensated controllinkage assembly 133 in accordance with one embodiment of the invention.As shown, FIG. 8 illustrates the mower 10 in an “uncompressed” condition(generally corresponding to the illustration of the suspension system103 as shown in FIG. 5, showing a suspension component 126 in agenerally extended, uncompressed condition). In some embodiments, theshock length of the embodiments shown in FIGS. 8 and 5 can be 10.5inches, and in this uncompressed condition, a 90 degree reference angleI is achieved between the couplings of bell crank 142 (shown as 142 aand 142 b) and a first axis 112 a on subframe 112. This positionsignifies a neutral condition of the mower when uncompressed.Conversely, FIG. 9 shows a “compressed” condition of the mower 10(generally corresponding to the illustration of the suspension system103 as shown in FIG. 6, showing a suspension component 126 in agenerally shortened, compressed condition). In some embodiments, theshock length of the embodiments shown in FIGS. 9 and 6 can be 8.5inches, and in this compressed condition, an 88.68 degree referenceangle I is achieved between operable couplings of bell crank 142 (shownas 142 a and 142 b, second axis 142 c) and the first axis 112 a onsubframe 112. In some embodiments, this change of angle I of 1.32degrees between the uncompressed and compressed conditions does notresult in the mower “lurching”, as discussed above. In some embodiments,the second end 138 b of the bell crank 138 is coupled to the first end140 a of the second control linkage 140, and the second end 140 b of thesecond control linkage 140 is coupled to the bell crank 142 coupled tothe conventional hydrostatic transaxle pump valve (not shown).

In some embodiments as described, the compensated control linkage system133 can compensate for movement of the subframe 112. Without thiscompensation, the degree change between the uncompressed and compressedconditions of the suspension system 103 would be significant enough tocause undesirable movement of the mower in some instances during theparked or neutral condition. While a change of angle I of 1.32 degreesas shown in FIG. 9, it is also possible for a compensated controllinkage assembly 133 to be configured to achieve various changes ofangle I, dependent upon the hydrostatic transaxle type and style. Forexample, an angular displacement of less than 1.32 degrees of angle I(e.g., zero degrees or substantially close to zero degrees) could beachieved, or an angular displacement of angle I of greater than 1.32degrees could be achieved for a hydrostatic transaxle capable oftolerating such a displacement without imparting movement on the drivewheels 104. In some embodiments, the compensated control linkageassembly 133 is configured and arranged to reduce and eliminate theamount of angle I change on the control paddle 134 when the suspensionsystem 103 including a suspension component 126 compresses anddecompresses, and the shock length decreases and increases. In somefurther embodiments (not shown), the amount of angle change can befurther reduced or eliminated with other adjustments to the linkagepositions and lengths. For example, by adjusting the length and traveldistance of the first control linkage 136, the second control linkage140, and by modifying the rotational circumference of the bell crank 138or bell crank 142, the amount of change of angle I can be adjusted.

FIG. 10A illustrates a perspective close-up view of the lower portion ofthe compensated control linkage assembly 133 and FIG. 10B illustrates aperspective close-up view of the upper portion of the compensatedcontrol linkage assembly 133. As shown, some embodiments of theinvention include a variety of support components. For example, as shownin FIG. 10B, bell crank 138 can be pivotably mounted to compensator arm310, which is further coupled to compensator link 300. As shown in FIG.10A, the compensator arm 310 can be coupled to a compensator lock 320.In some other embodiments, the compensated control linkage assembly 133including first control linkage 136, bell crank 138, second controllinkage 140 and bell crank 142 can be coupled to the main frame 102 andthe subframe 112 using alternative couplings.

Some embodiments can feature alternative suspension systems 103. Forexample, referring to FIG. 11, showing a perspective view of thesubframe 112 and hydrostatic transaxle 114, the hydrostatic transaxles114 are mounted to subframe 112 from below. In some other embodiments,as shown in FIG. 12 the hydrostatic transaxles 114 are mounted to asubframe 212 from above, which may account for variations in ZTR mowerdesign, size, etc. Some other embodiments can feature alternativesubframe 112 designs and alternative hydrostatic transaxles 114 designs.In some embodiments, the subframe 112 and hydrostatic transaxle 114 canbe coupled in other ways. One of ordinary skill in the art willunderstand that while the illustrated embodiments are directed to ZTRmowers, many embodiments of the invention are equally useful with othertypes of mowers as well.

As discussed earlier in reference to FIG. 3, illustrating a compressedstate of the suspension system 103, in some embodiments, each of thecomponents mounted on subframe 112 rotate about pivot axis 116 whencompressed. This includes idler pulley(s) 118, backside idler pulleys120 a,120 b, and driven pulleys 122 a,122 b on hydrostatic transaxles114. Hence, in some embodiments, idler pulley(s) 118 and backside idlerpulleys 120 a,120 b travel in the same pulley plane 400 as drivenpulleys 122 a,122 b upon rotation about pivot axis 116. Because thepulleys 118, 120 a, 120 b travel in the same pulley plane 400, in someembodiments, the change in the belt 132 angle is minimized when thesubframe 112 travels through its suspension arc, and therefore belt 132misalignment is also minimized. As described earlier, if the idlerpulleys 118, 120 a, 120 b were to travel or rotate about a differentplane than driven pulley 122 a,122 b (i.e. pulley plane 400) onhydrostatic transaxle 114, then significant belt 132 misalignment(caused by a belt 132 angle change) may encourage the belt 132 to “jump”off of the pulley system, thereby rendering the system inoperable.However, as described earlier in FIGS. 2 and 3, in some embodiments, theonly belt 132 angle change between pulleys in the present embodimentwould be between backside idler pulleys 120 a, 120 b and drive pulley110 mounted to the power take-off shaft 109. The risk of belt 132 “jump”due to misalignment is greatly diminished under this configurationbecause there is a significant distance between backside idler pulleys120 a, 120 b and drive pulley 110, thereby minimizing the belt 132 anglechange when subframe 112 travels through its suspension arc (i.e. duringa change of angle I). Furthermore, the significant distance between thedrive pulley 110 and the backside idler pulleys 120 a, 120 b maintainsthe angle of the endless belt 132 to 3 degrees or less, and preventsbelt 132 misalignment between these pulleys when subframe 112 travelsthrough its suspension arc. Moreover, backside idler pulleys 120 a,120 bhave a higher tolerance for belt 132 angle changes during operation thanother types of pulleys.

Some embodiments of the invention can be seen in FIG. 13, showing a topsectional view of the hydrostatic transaxle drive system components,including further details of the pulley and belt drive assembly 117.Specifically, FIG. 13 shows the location of the backside idlers 120a,120 b and their positional relationship with the engine 108, and thedrive pulley 110 (illustrated as endless belt 132 curvature over theengine 108) according to some embodiments of the invention. As shown, insome embodiments, the endless belt 132 can be coupled between the drivepulley 110 coupled to an internal combustion engine 108, backside idlerpulleys 120 a, 120 b, idler pulley 118, and driven pulley 122 a,122 b onhydrostatic transaxle 114. As detailed above, backside idler pulleys 120a,120 b, idler pulley 118, and driven pulleys 122 a,122 b on hydrostatictransaxle 114 each travel in the same pulley plane 400 while thesubframe 112 travels about its suspension arc. Thus, in someembodiments, the only change in angle of endless belt 132 occurs betweendrive pulley 110 coupled to internal combustion engine 108 and backsideidler pulley 120 a,120 b. However, in some embodiments, because of thesignificant distance between drive pulley 110 and backside idler pulleys120 a,120 b, made possible by the placement of backside idler pulleys120 a,120 b near pivot 115 and pivot axis 116 on suspended subframe 112,the change in belt 132 angle during suspended operation is minimized.Accordingly, the likelihood of belt slip or “jump” due to belt 132 anglechange is also minimized.

Further views of the various hydrostatic transaxle drive systemcomponents including the pulley and belt drive assembly 117 can be seenin FIGS. 14A and 14B. As shown, in some embodiments, one or morehydraulic drive systems can comprise a drive pulley 110, coupled to apower take-off shaft 109, coupled to an engine 108. In some embodiments,the drive pulley 110 can be coupled to one or more pulley and idlepulleys coupled to one or more hydrostatic transaxles 114. For example,as shown in FIGS. 14A and 14B, in some embodiments, the drive pulley 110can be coupled to backside idler pulleys 120 a,120 b, driven pulleys 122a,122 b, and belt idler pulley 118, all of which can be positioned asignificant distance from the drive pulley 110.

In some embodiments, idler pulley(s) 118 and backside idler pulleys 120a and 120 b are attached to the subframe 112 via a conventional spindle(not shown) to allow rotation of the pulleys. In some other embodiments,they can be attached via a plate 124 to front suspension mount 220. Insome embodiments, idler pulley(s) 118 and backside idler pulleys 120 a,120 b receive an endless belt 132 (not shown) that is driven by drivepulley 110 on the power take-off shaft 109 of internal combustion engine108. In some further embodiments, the endless belt 132 is also receivedby driven pulleys 122 a, 122 b coupled to the hydraulic pump (not shown)of hydrostatic transaxle 114. As described earlier, in some embodiments,the only belt 132 angle change between pulleys in the presentembodiments would be between backside idler pulleys 120 a, 120 b, anddrive pulley 110 mounted to the power take-off shaft 109. As previouslydescribed, the significant distance between backside idler pulleys 120a, 120 b and drive pulley 110 minimizes the belt 132 angle change whensubframe 112 travels through its suspension arc.

As described previously, in some embodiments, the ZTR mower 10 includesat least one power source such as an internal combustion engine 108, andin some embodiments, the internal combustion engine 108 can power atake-off shaft 109 coupled to at least one hydrostatic transaxle 114 viaan endless belt 132. In alternative embodiments, the at least one powersource can include a current source and the ZTR mower 10 can be driventhrough the rear drive wheels 104 by at least one electric driveassembly (not shown). For example, in some embodiments, a current sourcecomprising at least one battery (not shown) can be supported by the mainframe 102 and be capable of being electrically coupled to at least oneconventional electric drive assembly (not shown) including at least oneelectric motor (not shown). In some embodiments, the at least onebattery can be electrically coupled to the at least one electric motorusing at least one electrical harness (not shown).

In some embodiments, the at least one power source can include at leastone rechargeable battery. In some embodiments, the at least onerechargeable battery can be at least partially charged from an externalpower supply. For example, in some embodiments, the ZTR mower 10 canincluded a main frame 102 supporting at least one rechargeable batterythat can be at least partially charged from an electrical outlet oranother source of electricity. In some other embodiments, the ZTR mower10 can include an onboard power supply. For example, in someembodiments, the ZTR mower 10 can include rechargeable battery supportedby the main frame 102 that can be at least partially charged from aninternal combustion engine 108. In some embodiments, the engine 108 canbe electrically coupled to at least one onboard current generator or analternator (not shown) powered by the engine 108. In some embodiments,the onboard current generator can be capable of at least partiallyrecharging the at least one battery. In some other embodiments, theonboard current generator can be at least partially able to power the atleast one electric motor independently, or via the at least onerechargeable battery. In some embodiments, the at least one rechargeablebattery resides within the subframe 112, and the engine 108 is residesoutside of the subframe 112, supported on the main frame 102. In someother embodiments, the engine 108 can be electrically coupled to atleast one onboard current generator powered by the engine 108, furthercoupled to at least one rechargeable battery mounted to the subframe. Insome embodiments, the rechargeable battery can be recharged by theengine 108 via the current generator.

Some embodiments of the invention include a subframe 112 pivotallycoupled to a main frame 102 about a pivot axis of a ride-on equipmentthat includes at least one electric motor supported by the subframe 112.In some embodiments, the at least one electric motor is electricallycoupled to at least one battery positioned external to the subframe 112and supported by the main frame 102. In some embodiments, the electricmotor is configured and arranged to be powered by the at least onebattery for driving at least one wheel 104 and the pivot axis residessubstantially between the at least one electric motor and the at leastone battery.

In some other embodiments, the ZTR mower 10 can include at least onedrive shaft (not shown) coupled to at least one drive wheel 104. In someembodiments, the main frame 102 includes at least one at least one powersource such as an internal combustion engine 108, and in someembodiments, the engine 108 can be coupled to the drive shaft. Someembodiments of the invention include a subframe 112 pivotally coupled toa main frame 102 about a pivot axis of a ride-on equipment. In someembodiments, the engine 108, supported by the main frame 102, butunsupported by the subframe 112, is coupled to at least one wheel 104coupled to the subframe 112. In some embodiments, the at least one wheelis driven by the drive shaft coupled to the engine 108 and the pivotaxis resides substantially between the at least one wheel and the engine108.

In some alternative embodiments of the invention, the subframe 112 canbe formed from two separate pivotal platforms, one for each hydrostatictransaxle, to allow for independent suspension of each drive wheel.Further, embodiments of the invention that include an independentsuspension of each drive wheel, other variations in the pulleyarrangement can be included to account for movement of two separatepivotal platforms. For example, in reference to FIGS. 15-23, someembodiments include an alternative suspension system 1103 that caninclude two independent first and second subframes 1112 a, 1112 b eachseparately coupled to a main frame 1102. This arrangement can enableeach hydrostatic transaxle to be mounted on a separate subframe so thatany coupled drive wheel can respond to motion and suspension forcesindependently.

FIG. 15 illustrates a partially transparent perspective view 1100 of aportion of a suspension system 1103 of a ZTR mower 10 in accordance withsome embodiments of the invention. For ease of understanding, manyconventional components commonly present in ZTR mowers (e.g., controlhandles, seat, mower deck, etc.) have been omitted from FIG. 15.However, one of ordinary skill in the art will readily understand thatsuch conventional components may be included in the embodimentsdescribed herein. In some embodiments, the suspension system 1103comprises a main frame 1102 that can support the front and rear wheelsof a mower (e.g., such as both the front caster wheels 106 and the reardrive wheels 104 of ZTR mower 10.) In this instance, the main frame 1102can be used in place of the main frame 102 within the ZTR mower 10 tosupport an internal combustion engine 1108, along with one or more drivesystems that can be configured to operate to move the ZTR mower 10(e.g., using drive wheels 104). Further, the main frame 1102 can supportother primary components, as well as one or more auxiliary componentsattached to the ZTR mower 10, such as the cutting blades of the frontcutter assembly 30 (shown in FIG. 1).

FIG. 16 illustrates a perspective view of components of the suspensionsystem 1103 of a ZTR mower 10 in accordance with some embodiments of theinvention, and FIG. 17 illustrates a top view of components of thesuspension system 1103 of a ZTR mower 10 in accordance with someembodiments of the invention. In some embodiments, the suspension system1103 can include a first subframe 1112 a coupled to a side 1102 a of themain frame 1102. In some embodiments, the first subframe 1112 a cancomprise a support member 1214 including a first end 1214 a and a secondend 1214 b. In some embodiments, the first subframe 1112 a can bepivotally mounted to the main frame 1102 to allow for translationalmovement of the subframe 1112 a with respect to the main frame 1102. Insome embodiments, a pivot 1115 a can be located proximate the first end1214 a that can enable the first subframe 1112 a to pivot around thepivot axis 1116 a when coupled to a portion or region of the main frame1102. Thus, in some embodiments, the first subframe 1112 a, and anythingsupported by the first subframe 1112 a, can be allowed to pivot aboutthe main frame 1102 on a pivot axis 1116 a using the pivot 1115 a.

In some embodiments, the suspension system 1103 can include anothersubframe independent of the first subframe 1112 a. For example, in someembodiments, the suspension system 1103 can include a second subframe1112 b coupled to another and/or opposite side of the main frame 1102(side 1102 b). In some embodiments, the second subframe 1112 b cancomprise a support member 1216 including a first end 1216 a and a secondend 1216 b. In some embodiments, the second subframe 1112 b can bepivotally mounted to the main frame 1102 to allow for translationalmovement of the subframe 1112 b with respect to the main frame 1102. Insome embodiments, a pivot 1115 b can be positioned proximate the firstend 1216 a. The pivot 1115 b can enable the second subframe 1112 b topivot around a pivot axis 1116 b when coupled to a portion or region ofthe main frame 1102. Thus, in some embodiments, the second subframe 1112b, and anything supported by the second subframe 1112 b, can be allowedto pivot about the main frame 1102 on a pivot axis 1116 b using thepivot 1115 b.

The position and coupling of the first and second subframes 1112 a, 1112b to the main frame 1102 can be further illustrated in FIGS. 18-22. Forexample, FIG. 18 illustrates an end view of a suspension system 1103 ofa ZTR mower 10 in accordance with some embodiments of the invention.FIG. 19 illustrates a side view of a suspension system 1103 of a ZTRmower 10 in accordance with some embodiments of the invention. Further,FIG. 20 illustrates a partially transparent side view of a suspensionsystem 1103 of a ZTR mower 10 in accordance with some embodiments of theinvention. FIG. 21 illustrates a perspective view of a suspension system1103 of a ZTR mower 10, and FIG. 22 illustrates a close up perspectiveview of a portion of a suspension system 1103 of a ZTR mower 10 inaccordance with some embodiments of the invention. Some views show thesuspension system 1103 including pivot axis 1116 a of the first subframe1112 a, and pivot axis 1116 b of the separate second subframe 1112 b. Insome embodiments, the pivots 1115 a, 1115 b can be positioned onopposite sides of the main frame 1102 so that the pivot axis 1116 a,1116 b are aligned and/or are substantially equal. In some otherembodiments, the pivots 1115 a, 1115 b can be positioned on oppositesides of the main frame 1102 so that the pivot axis 1116 a, 1116 b atleast partially overlap. In some further embodiments of the invention,the pivots 1115 a, 1115 b can be positioned on opposite sides of themain frame 1102 so that there is no overlap or alignment of the pivotaxis 1116 a, 1116 b.

In some embodiments, either or both of the first and second subframes1112 a, 1112 b can be further coupled to a motion absorbing suspensioncomponent. In some embodiments, the motion absorbing suspensioncomponent can include a compressible suspension component such as a coilspring-type suspension component alternative, e.g., rubber and/or otherelastomeric polymer, one or more dampeners, hydraulics, flexures, one ormore air or other gas cushions, a spring only, dampener only, etc. Forexample, in some embodiments, the second end 1214 b of the supportmember 1214 can couple to a region of the main frame 1102 through a coilspring-type suspension component 1125. In some embodiments, the coilspring-type suspension component 1125 can comprise a second end 1125 bcoupled to the second end 1214 b of the support member 1214. Further, insome embodiments, a first end 1125 a of the coil spring-type suspensioncomponent 1125 can couple to a portion of the main frame 1102. In somefurther embodiments, the second end 1216 b of the support member 1216can couple to another portion or region of the main frame 1102 through acoil spring-type suspension component 1126. In some embodiments, thecoil spring-type suspension component 1126 can comprise a second end1126 b coupled to the second end 1216 b of the support member 1216, anda first end 1126 a of the coil spring-type suspension component 1126 cancouple to a region of the main frame 1102.

In some embodiments, either or both of the first and second subframes1112 a, 1112 b can support one or more transaxle assemblies. In someembodiments, one or more of the transaxle assemblies can be driven orpowered by the engine 1108 using one or more drive pulleys, including adrive pulley 1110 driven by the engine 1108 via a power take off shaft1109. In some embodiments, the transaxle assemblies can contain both ahydraulic pump, a hydraulic valve (not shown), and a hydraulic motor(not shown) for powering the drive wheels 104 of the ZTR mower 10. Forexample, in some embodiments, a hydrostatic transaxle 1114 a can becoupled to the first subframe 1112 a. In some embodiments, a hydrostatictransaxle 1114 a can be coupled to the support member 1214 between thefirst end 1214 a and the second end 1214 b. In some embodiments, aportion of the hydrostatic transaxle 1114 a or a coupled component ofthe hydrostatic transaxle 1114 a can pass through the support member1214 to drive and/or support a driving component such as a wheel. Forexample, in some embodiments, a drive axle 1114 c can pass through thesupport member 1214 to enable a drive wheel to be coupled to the driveaxle 1114 c. Further, in some embodiments, a hydrostatic transaxle 1114b can be coupled to the second subframe 1112 b adjacent or proximate theopposite side of the main frame 1102. In some embodiments, a hydrostatictransaxle 1114 b can be coupled to the support member 1216 between thefirst end 1216 a and a second end 1216 b. In some embodiments, a portionof the hydrostatic transaxle 1114 b or a coupled component of thehydrostatic transaxle 1114 b can pass through the support member 1216.For example, in some embodiments, a drive axle 1114 d can pass throughthe support member 1216 to drive and/or support a driving component suchas a wheel. In some further embodiments, auxiliary components attachedto the ZTR mower 10 (such as the cutting blades) can be driven via oneor more drive pulleys, including an auxiliary drive pulley 1111 drivenby the engine 1108 via a power take off shaft 1109 (see FIG. 20).

In some embodiments, the engine 1108 can drive or power either or bothof the hydrostatic transaxles 1114 a, 1114 b using a drive pulley 1110driven by the engine 1108. For example, referring to FIGS. 16 and 17, insome embodiments, the drive pulley 1110 can drive either or both of thehydrostatic transaxles 1114 a, 1114 b with the assistance of one or morepulleys mounted to portions of the first and second subframes 1112 a,1112 b. For example, some embodiments include a backside idler pulley1120 a coupled to pulley support 1218 of the first subframe 1112 a. Insome embodiments, the pulley support 1218 can be positioned generallyperpendicular to the first subframe 1112 a, extending from the supportmember 1214 towards the second subframe 1112 b. Further, in someembodiments, the second subframe 1112 b can include a pulley support1219, to which a backside idler pulley 1120 b can be mounted. In someembodiments, the pulley support 1219 can be positioned generallyperpendicular to the second subframe 1112 b, extending from the supportmember 1216 towards the first subframe 1112 a. In some embodiments, thebackside idler pulleys 1120 a and 1120 b can be attached to pulleysupports 1218, 1219 with a spindle or other conventional mechanism tofacilitate rotation of the backside idler pulleys 1120 a, 1120 b.

Some embodiments can include at least one belt idler pulley 1118 mountedto the main frame 1102. In some embodiments, the relative movement andposition and/or tension of one or more of the backside idler pulleys1120 a and 1120 b with respect to the belt idler pulley 1118 can betensioned or adjusted using one or more tension springs. For example, insome embodiments, one end of a tensioner spring 1425 can be coupled toan eyebolt 1426 of the belt idler pulley 1118, with a second end of thetensioner spring 1425 coupled to the shaft 1121 of the backside idlerpulley 1120 b. In some embodiments, tension can be adjusted by movingthe eyebolt 1426. For example, by increasing the distance between theeyebolt 1426 and the shaft 1121, the tension in the tensioner spring1425 can be increased. Further, by decreasing the distance between theeyebolt 1426 and the shaft 1121, the tension in the tensioner spring1425 can be decreased. Further, in some embodiments, a second end 1402of a swing arm 1400 can be coupled to the shaft 1121 of the backsideidler pulley 1120 b and the second end of the tensioner spring 1425,while the first end 1404 of the swing arm 1400 can be coupled to thepulley support 1219.

In some embodiments, power can be transmitted from an engine 1108 to thedrive pulley 1110 via an endless belt 1132. In some embodiments, theendless belt 1132 can be an “A” section belt, although in otherembodiments, a “V” section belt, a flat belt, or other type of belt canbe used. For example, in some embodiments, idler pulley(s) 1118 andbackside idler pulleys 1120 a, 1120 b can receive an endless belt 1132that can be driven by the engine 1108 through the drive pulley 1110. Insome embodiments, the endless belt 1132 can also be received by one ormore pulleys coupled to either or both of the hydrostatic transaxles1114 a,1114 b. For example, in some embodiments, the endless belt 1132can be received by driven pulley 1122 a of the hydrostatic transaxle1114 a and/or driven pulley 1122 b of the hydrostatic transaxle 1114 b.Thus, in some embodiments of the invention, through this pulley-beltcoupling, power from an internal combustion engine 1108 can betransferred to either or both hydrostatic transaxles 1114 a, 1114 b.When assembled within the ZTR mower 10, this configuration can enabledrive wheels 104 to be independently suspended by the first and secondsubframes 1112 a, 1112 b, and independently driven by the hydrostatictransaxles 1114 a, 1114 b. In some other embodiments, alternativemethods of driving hydrostatic transaxles 1114 a, 1114 b, such asthrough a universal drive shaft can be used.

In some embodiments, when the ZTR mower 10 is equipped with thesuspension system 1103, and the mower 10 traverses a terrain, or isloaded and unloaded, the main frame 1102 can move with respect to eitheror both of the first and second subframes 1112 a, 1112 b. For example,when an operator mounts the ZTR mower 10, or if additional weight orequipment is loaded onto the ZTR mower 10, the frame 1102 can move withrespect to either or both of the first and second subframes 1112 a, 1112b. Furthermore, during loading of the ZTR mower 10, in some embodiments,the coil spring-type suspension components 1125, 1126, coupled to bothmain frame 1102 can compress, and the first and second subframes 1112 a,1112 b can pivot about the pivot axis 1116 a, 1116 b on pivots 1115 a,1115 b respectively.

In some embodiments, the backside idler pulley 1120 a can pivot on thepivot 1115 a around the pivot axis 1116 a while coupled to a portion orregion of the main frame 1102. Therefore, in some embodiments, the firstsubframe 1112 a can allow the backside idler pulley 1120 a to pivot withrespect to the belt idler pulley 1118. Further, the backside idlerpulley 1120 b can pivot using pivot 1115 b around the pivot axis 1116 bwhile coupled to a portion or region of the main frame 1102. Therefore,in some embodiments, the second subframe 1112 b can allow the backsideidler pulley 1120 b to pivot with respect to the belt idler pulley 1118.Further, the backside idler pulleys 1120 a, 1120 b can pivot withrespect to each other and the belt idler pulley 1118.

Further details of the pivots 1115 a, 1115 b are illustrated in FIG. 23which illustrates a close up detailed sectional view of a suspensionsystem 1103 of a ZTR mower 10 in accordance with some embodiments of theinvention. This view illustrates one side of the suspension 1103illustrating detail of a pivot 1115 b and pivot axis 1116 b of thesecond subframe 1112 b, however it is representative of the pivot 1115 aand pivot axis 1116 a of the second subframe 1112 a. In someembodiments, the pivot 1115 b can be supported by portions of the mainframe 1102 as shown, and can enable the second subframe 1112 b to rotateor pivot with respect to the main frame 1102. For example, the pivot1115 b can be supported by an outer section 1102 c of the main frame1102 passing through one or more bearings 90 positioned between sectionsof the second subframe 1112 b, and supported at the other end by aninner portion 1102 d of the main frame. For example, in someembodiments, the pivot 1115 b can pass through pivot sleeve 80 b housingthe bearings 90. Thus, in some embodiments, the second subframe 1112 bto rotate or pivot with respect to the main frame 1102 by rotating orpivoting on the bearings 90.

It will be appreciated by those skilled in the art that while theinvention has been described above in connection with particularembodiments and examples, the invention is not necessarily so limited,and that numerous other embodiments, examples, uses, modifications anddepartures from the embodiments, examples and uses are intended to beencompassed by the claims attached hereto. The entire disclosure of eachpatent and publication cited herein is incorporated by reference, as ifeach such patent or publication were individually incorporated byreference herein. Various features and advantages of the invention areset forth in the following claims.

What is claimed is:
 1. A transaxle drive system for ride-on equipment,the transaxle drive system comprising: a frame supporting at least onepower source and at least two subframes, the at least one power sourceincluding at least one drive pulley; a plurality of transaxle assembliesconfigured and arranged to be driven by at least a portion of at leastone belt from the at least one drive pulley, the plurality of transaxleassemblies comprising: a first transaxle assembly supported by a firstsubframe of the at least two subframes, the first transaxle assemblycoupled to the at least one drive pulley with at least a portion of atleast one belt; a second transaxle assembly supported by a secondsubframe of the at least two subframes, the second transaxle assemblycoupled by at least a portion of at least one belt to the at least onedrive pulley; and wherein the plurality of transaxle assemblies areconfigured and arranged to be independently pivoted with respect to eachother, the frame, and the power source.
 2. The transaxle drive system ofclaim 1, wherein the at least one power source includes at least oneauxiliary drive pulley coupled to a power take-off shaft.
 3. Thetransaxle drive system of claim 2, wherein the at least one auxiliarydrive pulley is positioned between the plurality of transaxle assembliesand rear wheels of a mower.
 4. The transaxle drive system of claim 3,wherein the mower includes a mower deck positioned between front andrear wheels of the mower, the mower deck coupled to and supported by theframe.
 5. The transaxle drive system of claim 4, wherein the mower deckcomprises a cutter assembly coupled to and configured to be driven bythe auxiliary drive pulley using at least one endless belt.
 6. Thetransaxle drive system of claim 1, wherein at least one of the subframesis coupled to the frame using at least one compressible component. 7.The transaxle drive system of claim 6, wherein the at least onecompressible component comprises rubber or other elastomeric polymer. 8.The transaxle drive system of claim 1, wherein the plurality oftransaxle assemblies include drive axles configured and arranged toenable drive wheels to be independently suspended by the at least twosubframes.
 9. The transaxle drive system of claim 1, wherein the atleast two subframes are positioned coupled to opposite sides of theframe.
 10. The transaxle drive system of claim 5, wherein the pluralityof transaxle assemblies are positioned between the cutter assembly andthe at least one auxiliary drive pulley.
 11. The transaxle drive systemof claim 1, wherein the subframes each include a pivot coupled to theframe about a pivot axis.
 12. The transaxle drive system of claim 11,wherein the pivot axis of each subframe are parallel.
 13. The transaxledrive system of claim 1, wherein at least one of the first transaxleassembly and second transaxle assembly comprises a hydrostatictransaxle.
 14. The transaxle drive system of claim 1, wherein at leastone of the first transaxle assembly and second transaxle assembly areconfigured and arranged to be belt-driven by the at least one powersource during pivotal motion about the frame.
 15. The transaxle drivesystem of claim 1, further comprising a pulley and belt drive assembly,the pulley and belt drive assembly including: at least one belt idlerpulley positioned outside of the subframes and supported by the frame;and wherein the at least one belt is an endless belt, the at least oneendless belt coupled with the at least one belt idler pulley and atleast one driven pulley, the at least one driven pulley positionedsuspended by at least one of the subframes.
 16. The transaxle drivesystem of claim 15, wherein the pulley and belt drive assembly furthercomprises at least one backside idler pulley coupled to the least oneendless belt.
 17. The transaxle drive system of claim 15, wherein the atleast one endless belt is further coupled with the at least one drivepulley; and wherein the at least one backside idler pulley is configuredand arranged to pivot with respect to the at least one drive pulley. 18.The transaxle drive system of claim 1, wherein the at least one drivepulley is driven by a drive shaft of the at least one power source, thedrive shaft including an axis of rotation.
 19. The transaxle drivesystem of claim 18, wherein the first transaxle assembly is configuredand arranged to be driven by the at least one power source whilepivoting about the axis of rotation.
 20. The transaxle drive system ofclaim 19, wherein the second transaxle assembly is configured andarranged to be driven by the at least one power source while pivotingabout the axis of rotation and the first transaxle assembly.